Abstract In order to provide scientific data for establishing a dugong (Dugong dugon) nature reserve in Hainan Province,we investigated the marine environment and the status of dugongs along the west cost of Hainan Island, November 2001-October 2002. Questionnaire surveys in Guangxi and Guangdong as well as Hainan were also conducted during this time. We documented dugongs in the coastal waters of Hepu County, Guangxi Zhuang Autonomous Region,but found no dugongs along the west coast of Hainan. Seagrass beds in the traditional habitats of dugong were destroyed and had disappeared in some areas. We believe that conditions are not presently conducive to establishment of a dugong nature reserve in Hainan. The dugong population has been reduced by human activities and ecosystem deterioration. Effective measures and an integrated management system are needed to conserve dugongs and their habitats.